Temperature control valve



Oct. 25, 1927. r 6,5 8

R. MAC-LAREN TEMPERATURE CONTROL VALVE Filed Sept. 11, 1924 Patented Oct. 2 5, 1927;

- UNITEDJSTATES.

PATEI:JT, OFF-ICE.

s 30mm nhicnannmor .CULROSS, FIFE, scorLANnI TEMPERATURE oonraor. VALVE I Application filed September 11, 1924, Serial No. 737,183, and in Great Britain October 81 1928.

' In order that my invention may be properly understood and readily carried into effeet, I have hereunto appended one sheet of drawings, of which Figure-1 is a sectional elevatlon of a temperature control valve constructed according to my invention. 1

Figure 2 is a plan of Figure 1. Q

Figure 3 is a detail elevation'of my improved control valve.

. Referring to, the drawings, A is the-bulb and B the .extension which is suitably screwed to a valve body H, the inner end of said extension being contained within the valve body H and being of parabolic. concave formation and being sealed by adlaphragm D of parabolic form to ensure absolute uniformity of movement at all control points. The passage G between the bulb A and extension B is gradually enlarged toward the sealing diaphragm D so that, 1n

the event of the expansion medium being.

solid at atmospheric temperature, no severe stresses are set up when the bulb A is sub jected to heat'in chamber to be controlled. A secondary diaphragm E which is also of parabolic concave curvature lies in close contact with the diaphragm D and is fitted with a pin F which carries the valve G,'a

springN being carried on the pin F be-' tween the diaphragm E and the valve G, so that the valve G and secondary diaphragm E may be kept apart at their extreme limits. This secondary diaphragm carrying pin is used in order to save the sealing diaphragm D being punctured to take thepin.

The valve body H has an inlet and outlet K and L. respectively and .has an adjustable valve seat I which is open and bell-mouthed at the top, an opening Q, in the hollow central portion being in communication with the outlet L. A small by pass opening J is also provided and is controlled by the screw J between the outlet and the inside of the valve body'I-I. The lower portion of the .P suitably connected to the valve body I-I,

an adjusting screw 0 being provided to raise or lower the valve seat I. This cover P' is enclosed in a case M which acts as a handle and is connected to it by a screw M The case M which encloses the bottom of the valve-body H is gnaduated at -M to form a register of adjustment. v

The operation of myinvention lows: o

The bulb A is charged with a suitable medium expansible by heat and said bulb, in

is as folpractice is enclosed in .a chamber which is' heated by the combustion of the gas which passes through the said valve. The gas en- L ters the 'valvebody. through the inlet K and passes therefrom to the valve seat I and from thence through the port Q through the outlet L and initially the apparatus is so adjusted and arranged that the port Q is entirely open when the .chamber in which the bulb A is located is at the desired temperature. In the event that the temperature of the bulb increases materially the expansible medium therein acts upon the 'diaphragm D and said diaphragm moves the valve member Gr toward the seat I thus tensioning the flow of gas from the in ct K to the outlet L as will be understood. In the event of an ab-' normal overheating of the bulb. A, the member G will close against the seat I.- The bypass j whenlopened by the valve j permits a minimum flow of'gas through the apparatus. under all conditions, as will be understood. y

.In. order that no stressing of parts occur whengoing from a high heat to a lower heat, a sliding movement of the valve G on the pin F is allowed for, the spring N coming into operation for a short period until the diaphragm E returns the requisite amount equivalent to' the lower heat in the, bulb A. 1 I

A temperature 'control using the sliding valve seat with natural working of the expansion medium throughout the whole range requires no spring action for varying the control point, that is, raising the temperature to the boiling point.

'- The handle and dial, thelatter overlapping the body to prevent dust, grease, and

the like collecting is graduated in degrees. The handle has the various temperature on the body.

cooking sections moulded on to the corresponding temperature. A pointer mark'is valve seat, an ex ansion bulb having a duct leading to said d1aphragm,- a valve movable by said diaphragm toward and from said valve seat, and means connecting said valve to said parabolic diaphra m for limited slidin axial movement, an a spring between said diaphragm and said valvev to normall hold the latter at the outer extent of its 'sli ing axial movement relative to the parabolic diaphragm.

2. Apparatus ofthe class described comrising a body havin a chamber therein and inlet and outlet openings, an adjustable valve seat in said body having a duct .;,and a port establishing communication between said duct and said outlet opening a parabolic diaphragm in said body opposite said valve seat, an expansion bulb having a duct leading to said diaphragm, and a valve movable .by said diaphragm toward and from said valve seat, said valve seat havin a'diametrically enlarged mouth communicating with said duct, said mouth presenting a rim extending therearound and against which said valve closes, a cover encasing the outer end of said stein and provided with means to adjust saidvalve seat, and a case in which said cover is arranged, said cover having screw-' threaded connection with said body and said cover and body havingthe one a graduated scale and the other a fixed point for cooperation with said scale.

3. Apparatus of the class described comprising a body having a chamber therein and inlet and outlet openings, an adjustable valveseat in said body having a duct and a port establishing communication between said duct and said outlet opening, a parabolic diaphragm in said body opposite said valve seat, an expansion bulb having a duct leading to said diaphragm, and a va ve movable by said diaphragm toward and from said valve seat, said va ve seat having a stem movable slidably in an opening with which the body is provided, a cover encasing the outer'end of said stem and a screw in said cover to adjust said valve seat, and a case in which said cover is arranged, said cover having screw-threaded connection with said body and said cover and body having the.

one a graduated scale and the other'a fixed point for cooperatlon with \said scale.

'- In witness whereof I aflix my signature.

ROBERT 

